WIP on priv spec v1.9

2 files changed, 21 insertions, 25 deletions

diff --git a/v/entry.S b/v/entry.S
index ea05e73..f503764 100644
--- a/v/entry.S
+++ b/v/entry.S
@@ -13,30 +13,25 @@
 #define STACK_TOP (_end + 131072)
 
   .section ".text.init","ax",@progbits
-  .align 6
-entry_from_user:
-  mrts
 
-  .align 6
-entry_from_supervisor:
-  csrr t0, mcause
-  addi t0, t0, -CAUSE_SUPERVISOR_ECALL
-  beqz t0, handle_tohost
-  j wtf
+reset_vector:
+  j handle_reset
 
-  .align 6
-entry_from_hypervisor:
+  /* NMI vector */
+nmi_vector:
   j wtf
 
-  .align 6
-entry_from_machine:
+trap_vector:
+  # we can safely clobber caller-saved registers here, because we were
+  # either invoked via do_tohost or we are about to bail out
   csrr t0, mcause
-  addi t0, t0, -CAUSE_MACHINE_ECALL
-  beqz t0, handle_tohost
+  li t1, CAUSE_SUPERVISOR_ECALL
+  beq t0, t1, handle_tohost
+  li t1, CAUSE_MACHINE_ECALL
+  beq t0, t1, handle_tohost
   j wtf
 
-  .align 6
-power_on_reset:
+handle_reset:
   la sp, STACK_TOP - SIZEOF_TRAPFRAME_T
   csrw mscratch, sp
   li a1, 1337
@@ -45,7 +40,6 @@ power_on_reset:
 
   .globl  pop_tf
 pop_tf:
-  csrc sstatus, SSTATUS_IE
   LOAD  t0,33*REGBYTES(a0)
   csrw  sepc,t0
   LOAD  x1,1*REGBYTES(a0)
diff --git a/v/vm.c b/v/vm.c
index 7b5ba6c..561578e 100644
--- a/v/vm.c
+++ b/v/vm.c
@@ -182,17 +182,19 @@ void vm_boot(long test_addr, long seed)
   // map user to lowermost megapage
   l1pt[0] = ((pte_t)user_l2pt >> PGSHIFT << PTE_PPN_SHIFT) | PTE_V | PTE_TYPE_TABLE;
   user_l2pt[0] = ((pte_t)user_l3pt >> PGSHIFT << PTE_PPN_SHIFT) | PTE_V | PTE_TYPE_TABLE;
-  write_csr(sptbr, l1pt);
+  write_csr(sptbr, (uintptr_t)l1pt >> PGSHIFT);
 
   // set up supervisor trap handling
   write_csr(stvec, pa2kva(trap_entry));
   write_csr(sscratch, pa2kva(read_csr(mscratch)));
-  // interrupts on; FPU on; accelerator on
-  set_csr(mstatus, MSTATUS_IE1 | MSTATUS_FS | MSTATUS_XS);
-  // virtual memory off; set user mode upon eret
-  clear_csr(mstatus, MSTATUS_VM | MSTATUS_PRV1);
-  // virtual memory to Sv39
-  set_csr(mstatus, (long)VM_SV39 << __builtin_ctzl(MSTATUS_VM));
+  write_csr(medeleg,
+    (1 << CAUSE_USER_ECALL) |
+    (1 << CAUSE_FAULT_FETCH) |
+    (1 << CAUSE_FAULT_LOAD) |
+    (1 << CAUSE_FAULT_STORE));
+  // on ERET, user mode w/interrupts on; FPU on; accelerator on; VM on
+  write_csr(mstatus, MSTATUS_UIE | MSTATUS_FS | MSTATUS_XS |
+                     (VM_SV39 * (MSTATUS_VM & ~(MSTATUS_VM<<1))));
 
   seed = 1 + (seed % MAX_TEST_PAGES);
   freelist_head = pa2kva((void*)&freelist_nodes[0]);